package redis import ( "time" ) type rateLimiter struct { C chan struct{} } func newRateLimiter(limit time.Duration, chanSize int) *rateLimiter { rl := &rateLimiter{ C: make(chan struct{}, chanSize), } for i := 0; i < chanSize; i++ { rl.C <- struct{}{} } go rl.loop(limit) return rl } func (rl *rateLimiter) loop(limit time.Duration) { for { select { case rl.C <- struct{}{}: default: } time.Sleep(limit) } }